Semitransparent solar cells can provide not only efficient power‐generation but also appealing images and show promising applications in building integrated photovoltaics, wearable electronics, ...photovoltaic vehicles and so forth in the future. Such devices have been successfully realized by incorporating transparent electrodes in new generation low‐cost solar cells, including organic solar cells (OSCs), dye‐sensitized solar cells (DSCs) and organometal halide perovskite solar cells (PSCs). In this review, the advances in the preparation of semitransparent OSCs, DSCs, and PSCs are summarized, focusing on the top transparent electrode materials and device designs, which are all crucial to the performance of these devices. Techniques for optimizing the efficiency, color and transparency of the devices are addressed in detail. Finally, a summary of the research field and an outlook into the future development in this area are provided.
Recent developments of semitransparent organic solar cells, dye‐sensitized solar cells, and perovskite solar cells are reviewed with a focus on different device design, transparent top electrode materials, and the corresponding device fabrication techniques. Key issues related to the optimization of the efficiency, color, and transparency of the semitransparent photovoltaic devices are discussed in detail.
Poor stability of organic-inorganic halide perovskite materials in humid condition has hindered the success of perovskite solar cells in real applications since controlled atmosphere is required for ...device fabrication and operation, and there is a lack of effective solutions to this problem until now. Here we report the use of lead (II) thiocyanate (Pb(SCN)2) precursor in preparing perovskite solar cells in ambient air. High-quality CH3NH3PbI3-x(SCN)x perovskite films can be readily prepared even when the relative humidity exceeds 70%. Under optimized processing conditions, we obtain devices with an average power conversion efficiency of 13.49% and the maximum efficiency over 15%. In comparison with typical CH3NH3PbI3-based devices, these solar cells without encapsulation show greatly improved stability in humid air, which is attributed to the incorporation of thiocyanate ions in the crystal lattice. The findings pave a way for realizing efficient and stable perovskite solar cells in ambient atmosphere.
Grain boundaries in organic-inorganic halide perovskite solar cells (PSCs) have been found to be detrimental to the photovoltaic performance of devices. Here, we develop a unique approach to overcome ...this problem by modifying the edges of perovskite grain boundaries with flakes of high-mobility two-dimensional (2D) materials via a convenient solution process. A synergistic effect between the 2D flakes and perovskite grain boundaries is observed for the first time, which can significantly enhance the performance of PSCs. We find that the 2D flakes can conduct holes from the grain boundaries to the hole transport layers in PSCs, thereby making hole channels in the grain boundaries of the devices. Hence, 2D flakes with high carrier mobilities and short distances to grain boundaries can induce a more pronounced performance enhancement of the devices. This work presents a cost-effective strategy for improving the performance of PSCs by using high-mobility 2D materials.
Tin‐based perovskites with excellent optoelectronic properties and suitable band gaps are promising candidates for the preparation of efficient lead‐free perovskite solar cells (PSCs). However, it is ...challenging to prepare highly stable and efficient tin‐based PSCs because Sn2+ in perovskites can be easily oxidized to Sn4+ upon air exposure. Here we report the fabrication of air‐stable FASnI3 solar cells by introducing hydroxybenzene sulfonic acid or its salt as an antioxidant additive into the perovskite precursor solution along with excess SnCl2. The interaction between the sulfonate group and the Sn2+ ion enables the in situ encapsulation of the perovskite grains with a SnCl2–additive complex layer, which results in greatly enhanced oxidation stability of the perovskite film. The corresponding PSCs are able to maintain 80 % of the efficiency over 500 h upon air exposure without encapsulation, which is over ten times longer than the best result reported previously. Our results suggest a possible strategy for the future design of efficient and stable tin‐based PSCs.
Protective coating: A tin‐based perovskite solar cell with significantly improved stability to oxidation was prepared by introducing hydroxybenzene sulfonic acid or a salt thereof as an antioxidant additive into the perovskite precursor solution. The resulting perovskite grains are encapsulated by a SnCl2–additive complex layer.
Highly uniform and transparent polyaniline (PANI) electrodes that can be used as counter electrodes in dye-sensitized solar cells (DSSCs) were prepared by a facile in situ polymerization method. They ...were used to fabricate a novel bifacially active transparent DSSC, which showed conversion efficiencies of 6.54 and 4.26% corresponding to front- and rear-side illumination, respectively. Meanwhile, the efficiency of the same photoanode employing a Pt counter electrode was 6.69%. Compared to conventional Pt-based DSSCs, the design of the bifacial DSSC fabricated in this work would help to bring down the cost of energy production due to the lower cost of the materials and the higher power-generating efficiency of such devices for their capabilities of utilizing the light from both sides. These promising results highlight the potential application of PANI in cost-effective, transparent DSSCs.
A novel transparent and stable polypyrrole (PPy) electrode that can properly serve as a counter electrode for the bifacial dye-sensitized solar cell (DSSC) has been prepared by in situ polymerization ...of pyrrole monomer on FTO glass. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurement show the considerable catalytic activity of PPy counter electrode. The photovoltaic parameters of bifacial DSSCs are strongly dependent on the initial monomer concentration of pyrrole. The optimized PPy counter electrode has been fabricated under the initial monomer concentration of 0.3 M, a bifacial DSSC based on this PPy electrode shows conversion efficiencies of 5.74% and 3.06% corresponding to front- and rear-side illumination, respectively. Compared to the conventional Pt-based DSSCs, the design of bifacial DSSC with transparent PPy counter electrode improves the utilization ratio of incident light. Moreover, the considerable conversion efficiency and the good long-term stability of PPy-based device demonstrated by the stability test highlight the potential large-scale commercial application of this transparent PPy counter electrode.
► A transparent PPy film with electrochemical catalytic activity has been prepared. ► A bifacial DSSC based on this PPy film has been reported for the first time. ► The DSSC based on this PPy counter electrode shows excellent long-term stability. ► The application of this PPy film in DSSC would bring down the production cost.
A nanostructured platform that combines electrospun TiO2 nanofibers (TiNFs)‐deposited substrate and cell‐capture agent realizes significant capture of circulating tumor cells (CTCs). The enhanced ...local topographic interactions between the horizontally packed TiNFs deposited substrates and extracellular matrix scaffolds, in addition to anti‐EpCAM/EpCAM biological recognition, contributes to the significantly enhanced capture efficiency compared to flat surfaces.
The realization of highly efficient perovskite solar cells (PSCs) in ambient air is considered to be advantageous for low‐cost commercial manufacturing. However, it is fundamentally difficult to ...achieve comparable device performance to that obtained in an inert atmosphere, especially when the ambient humidity is high. Here, an effective precursor engineering that simultaneously employs non‐halide lead acetate and lead thiocyanate lead sources for fabricating high‐quality methylammonium lead iodide perovskite films in ambient air with enhanced moisture tolerance, is reported. The presence of Ac– and SCN– ions not only enables the facile formation of homogeneous and highly crystalized perovskite films, but also directs the uniform growth of the crystals along the (110) direction. Accordingly, a 20.55% efficiency is demonstrated, one of the best results for air‐processed MAPbI3 PSCs, which is also the highest value achieved with non‐halide lead sources. Furthermore, the unencapsulated device shows fivefold prolonged air stability (3600 h) compared to the conventional PbI2‐based PSC. Together with the use of non‐toxic antisolvent, this strategy is fully compatible with ambient air operation and thus of great potential for practical applications.
Herein, lead acetate and lead thiocyanate are explored as dual lead sources to prepare high‐quality methylammonium lead iodide perovskite films in ambient air through an eco‐friendly way, which results in unprecedented efficiency for perovskite solar cells prepared from non‐halide lead sources. In addition, the device also shows excellent air stability.
Organic‐inorganic halide perovskite solar cells (PSCs) are emerging new generation cost‐effective photovoltaic technology. However, the public concern about the toxic lead contained in state‐of‐art ...PSCs has cast a shadow on their prospect for commercialization. Therefore, increasing attention has been paid to lead‐free tin‐based perovskites, which have the potential to achieve comparable photovoltaic performance to their lead‐based counterparts. However, the development of high‐performance tin‐based PSCs is seriously undermined by the intrinsic poor stability of divalent tin in the perovskites. With the efforts to overcome the stability issue, encouraging ~10% efficiencies have been currently achieved. In this review, we summarize the recent advances toward efficient and stable tin‐based PSCs and offer a perspective for future study.
Increasing attention has been paid to tin‐based perovskite solar cells (PSCs) due to the potential to achieve high photovoltaic performance without including toxic lead. However, the device performance is seriously undermined by the poor stability of divalent tin in the perovskites. Here, we summarize the recent advances toward efficient and stable tin‐based PSCs and offer a perspective for future study.
The crystallinity of organic–inorganic hybrid lead halide perovskite active layers is critical to the performance of perovskite solar cells (PSCs). However, it is a challenge to control the ...crystallization process of perovskite films by solution process. Here, the fabrication of high‐efficiency PSCs by employing lead acetate (PbAc2) as an additive in the perovskite precursor is demonstrated for the first time. By adding a few percent of PbAc2 (molar ratio with respect to PbI2) into the precursors, the perovskite crystallization process is significantly retarded, leading to pinhole‐free perovskite films with large grains and low defect densities. As result, the power conversion efficiencies and stability of the PSCs are substantially improved. This work provides a convenient and unique approach for preparing high‐quality perovskite films that can be used in photovoltaics as well as other optoelectronic devices.
Lead Acetate (PbAc2) is introduced as an additive in perovskite precursors to form a stable intermediate phase via hydrogen bonding and retard the crystallization process of perovskite films successfully. Consequently, the crystallinity and morphology of the perovskite films are improved substantially and the average power conversion efficiency of the resulting devices is relatively enhanced for 13.6%.
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